*2.3. Statistical Analysis*

Continuous variables were reported as mean ± standard error of the mean (SEM) or as median (range) depending on data distribution. The normality of the data was evaluated by D'Agostino-Pearson test. The comparison of continuous variables between independent groups was done by employing the Mann-Whitney test. The comparison of paired measurements was carried out by *t*-student test for paired measurements or by Wilcoxon test, depending on the distribution of the data. For dichotomous

qualitative variables, the Chi-square test was performed. A logistic regression was performed in order to derive the odds ratio (OR), with its 95% confidence interval, as a measure of the strength of association of the two variables. A *p* value of less than 0.05 was considered significant. The statistical analysis was performed with MedCalc Statistical Software version 18.9.1 (MedCalc Software bvba, Ostend, Belgium; http://www.medcalc.org; 2018).
